132 Things not generally Known. 



changes of position in the grave, bursting open the coffin-lids, turning 

 over, crossing of limbs, &c., formerly attributed to the coming to life of 

 persons buried who were not dead, is now ascertained to be due to the 

 same cause. The chemical change into adipocere, and the evolution of 

 gases, produce these movements of dead bodies. Mr. Trail Green. 



THE MOST ANCIENT FISHES. 



Among the important results of Sir Roderick Murchison's 

 establishment of the Silurian system is the following : 



That as the Lower Silurian group, often of vast dimensions, has 

 never afforded the smallest vestige of a Fish, though it abounds in nu- 

 merous species of the marine classes, corals, cnnoidea, mollusca, and 

 Crustacea ; and as in Scandinavia and Russia, where it is based on rocks 

 void of fossils, its lowest stratum contains facoids only, Sir R. Mur- 

 chison has, after fifteen years of laborious research stea iily directed to 

 this point, arrived at the conclusion, that a very long period elapsed 

 after life was breathed into the waters before the lowest order of verte- 

 brata was created ; the earliest fishes being those of the Upper Silurian 

 rocks, winch he was the first to discover, and which he described " as 

 the most ancient beings of their class which have yet been brought to 

 light." Though the Lower Silurian rocks of various parts of the world 

 have since been ransacked by multitudes of prying geologists, who have 

 exhumed from them myriads of marine fossils, not a single ichthyolite 

 has been found in any stratum of higher antiquity than the Upper 

 Silurian group of Murchison. 



The most remarkable of all fossil fishes yet discovered have 

 been found in the Old Red Sandstone cliffs at Dorpat, where 

 the remains are so gigantic (one bone measuring two feet nine 

 inches in length) that they were at first supposed to belong to 

 saurians. 



Sir Roderick's examination of Russia has, in short, proved 

 that the ichthyolites and mollusks which, in Western Europe, are 

 separately peculiar to smaller detached basins, were here (in the 

 British Isles} cohabitants of many parts of the same great sea. 



EXTINCT CARNIVOROUS ANIMALS OF BRITAIN. 



Professor Owen has thus forcibly illustrated the Carnivorous 

 Anim ils which preyed upon and restrained the undue multi- 

 plica ion of the vegetable feeders. First we have the bear 

 family, which is now represented in this country only by the 

 badger. We were once blest, however, with many bears. One 

 species seems to have been identical with the existing brown 

 bear of the European continent. Far larger and more formidable 

 was the gigantic cave-bear ((Jrsus spelceus), which surpassed in 

 size his grisly brother of North America. The skull of the cave- 

 bear differs very much in shape from that of its small brown 

 relative just alluded to ; the forehead, in particular, is much 

 higher, to be accounted for by an arrangement of air-cells simi- 

 lar to those which we have already remarked in the elephant. 



